CURRENT ISSUE

High-energy astrophysics meeting: X-rays and more X-rays

I’m at the 13th meeting of the High Energy Astrophysics Division of the American Astronomical Society for a few days. Some 400 astronomers have been updating one another on the state of their studies, and I’m here to listen in and learn about the current projects (plus I’ll receive the award for the David N. Schramm science journalism award at tomorrow’s banquet).

The Nuclear Spectroscopic Telescope ARray (NuSTAR) is focusing “hard” X-rays to create images with detail never before seen at these energies. Blue in this image of supernova remnant Cassiopeia A represents NuSTAR data, while red and green show lower-energy X-rays imaged by the Chandra X-ray Observatory. // photo by NASA/JPL-Caltech/DSS

Yesterday and today I heard a lot about X-rays — specifically the highest-energy X-rays that the Nuclear Spectroscopic Telescope ARray (NuSTAR) detects. This observatory launched June 13, 2012, with the purpose of focusing “hard” X-rays, which have energies between 6 and 79 kilo-electron volts (keV, visible light has energy of about 2 eV). While some past space telescopes could detect energy in this regime, they couldn’t focus it to create an image to show details of sources. Because NuSTAR is operating in a region not well-studied, it has led to some exciting research.

A number of scientists discussed their ongoing studies — one group is using NuSTAR to observe starburst galaxies (like M82) while another is tracing titanium-44 produced in supernova explosions. A handful of poster presentations also discuss first results from the NuSTAR program, and I hope to check those out tomorrow. (At this meeting, the posters remain up all week, which is different from the full AAS conferences, where you get just one day for more than 100 posters. I certainly prefer this more relaxed pace to check out the poster presentations.)

Scientists also have spent time discussing future X-ray missions. It’s no secret that science funding is taking a hit right now due to federal budget constraints, and a project of the scale of the Chandra X-ray Observatory and the Hubble Space Telescope will require international cooperation due to cost: $1 billion is a hefty price tag, and a large percentage of NASA’s astrophysics funding is currently going toward the James Webb Space Telescope. So astronomers are looking beyond that time frame — into the 2020s and even 2030s — to plan missions involving NASA, the European Space Agency (ESA), the Japan Aerospace Exploration Agency (JAXA), and perhaps smaller institutions as well.

This illustration shows Astro-H, the next large-scale X-ray observatory. Led by the Japan Aerospace Exploration Agency (JAXA), the telescope is planned to launch in 2015. // photo by Akihiro Ikeshita/JAXA

Astro-H is a near-term project currently in development with a planned launch of 2015. JAXA is the lead, while NASA and ESA are contributing instruments. This telescope will include instruments to focus both soft and hard X-rays, a wide-field soft X-ray imager, and others.

Ideas a decade or two in the future include the Large Observatory For X-ray Timing, a European-led mission that will compete for a launch between 2022 and 2024 with ESA’s Cosmic Vision program, and the Advanced Spectroscopic and Imaging Observatory (AXSIO), a NASA proposed project that would be simpler than the International X-ray Observatory (IXO) that was ranked fourth in the National Academies-led Decadal Survey.

The future of this exciting science is certainly something to keep watch on. And the high energies probed by X-ray observatories can continue to tell astronomers about black holes (both the stellar-mass and supermassive varieties), supernova explosions, and neutron stars — all are objects that probe the extremes of physics.